Climate measurement can mislead

Biblical quotations quite rightly arouse suspicion. The Bible is hardly science- or evidence-based. Invariably biblical quotes are used by people who want to persuade you of some obviously asinine, apocalyptical or illogical proposition.

But, on this isolated occasion, I cannot resist Matthew’s words: “With what measure ye mete, it shallbe measured to you.”

And, yes, I am going to use the quote in reference to an apocalypse – a lifting of the veil so we can all see the impending catastrophe.

You see, the measure with which we are mete-ing climate change is deceptive. It lulls us into complacency and therefore might result, as Ross Garnaut warns, in too little being done too late to save us from environmental and economic havoc.

Measurements are critical. Our perceptions are based on measurements. We imagine a tree measuring 300 feet to be taller than one measuring 100 metres, yet it is shorter.

The metric system is exquisite if you are brought up on it from childhood so it is hard-wired in your brain like a language learned in childhood. If not, you can lose and never regain concepts because the units of measurement have changed. Not many Australians over the age of 50 have much idea of the difference between a gas-guzzling or economical car is because the conversion of two measures – miles and gallons – into litres and kilometres is hard enough, but when the expression is further converted from relating to a constant volume of fuel (a gallon) to a constant of distance (100 kilometres) it is just too hard.

Even now, most over 50s know that 35 miles a gallon is pretty good, but would have no idea what that was in litres per 100 kilometres.

I suspect part of the nonchalance about climate change might be because of the way we measure it.

The much-bandied-about two or three degrees rise in global temperature does not sound much. People live affluent lives in Singapore – average daily maximum around 30 degrees – and in Stockholm – average daily maximum seven degrees, so why should we worry about two or three degrees.

But the measurement invites the belittlement of the danger. We should stop measuring climate projections in degrees Celsius. We should start using percentages.

The degree measurement is even worse in the United States which uses Fahrenheit to measure temperature. Typical mild days are in the low 70s. Sure, a Fahrenheit degree is slightly smaller than a Celsius one (five-ninths to be precise), so a global warming of two degrees Celsius is roughly three degrees Fahrenheit, so that sounds more, but the three-degree warming is seen by the average American as three degrees out of 70 or so. It is seen as a trifle. Small wonder polls suggest Americans as less concerned about global warming than Europeans.

Even in countries that measure temperature in Celsius, a two-degree warming does not seem much.

Measuring by percentages, on the other hand, might engender some much-needed urgency in climate policy. It has some scientific difficulty. Upon what do you base your percentage change?

As a crude measure you could start with the proposition that the average world temperature is about 15 degrees. If you add two degrees to that, it would be 13 per cent. Ouch. When you describe a world 13 per cent hotter than it is now, people would start to take notice. Two degrees they can ignore.

Of course, we have air temperature and sea temperatures to contend with. Raising the temperature of air takes less energy than raising the temperature of water. There are other measurement difficulties, but they should be met because the present measurement method results in too much complacency in the face of danger.

Let me illustrate the point with another example. The way we measure speed invites complacency in the face of significant danger. It is quite idiotic that speedometers in cars go to 240km/h, when the maximum speed limit in most of Australia is 110km/h an hour.

The speedometer should only go to about 140km/h. The trouble with present speedometers is they create misconceptions. The first misconception is that 110km/h is really only about half-way, whereas the perception you want to provide is that 110km/h is starting to push the limits.

The second misconception is that the difference between, say, 50km/h and 60km/h is quite small. It comprises a very small portion of the speedometer’s dial. But the difference in stopping distance and injury between the two speeds is large indeed.

Indeed, other than suicide, road crash is the most likely cause of non-disease death in Australia. Driving about is the most dangerous thing we do, yet we measure the speed of our driving (the main source of danger) in a way that invites complacency.

As it happens, it seems that Australians are ahead of policy makers on climate change and appear to be willing to sacrifice some economic growth to do something about it. Perhaps that is because media likes a dramatic story, so climate change gets greater coverage than more mundane dangers.

But that could be shrugged off when immediate costs are put against a distant future risk.

So we need to balance of risks and costs intelligently. In any balancing of risks and costs – car speed and time or cheap carbon now against expensive damage later — measurement of the thing posing the risk should be done in a realistic way, not in a way that enables it to be shrugged off.

Two degrees – no worries. Thirteen per cent – ouch.